I've been doing a spring cleaning (6 months late, I know) and I re-discovered years-old tea in the kitchen, some stored in air-tight or decent-ish containers, others not, that I couldn't bring myself to give up. Out of curiosity, I tried some TGY oolong from 2010 or 2011. It tasted fine to me, although in fairness, it's been a long time since I've had fresh oolong so maybe I've just forgotten how much better it tasted when I got it.

I'm an intermittent tea-drinker. I'll go many months or over a year drinking it consistently, but if there's some change in my life and I get out of the habit I go months, or longer - my most recent and longest stretch was nearly 2 years - without. I'm currently trying to rekindle my tea habit. I know I could pitch everything and start over, but I wanted to revisit these first and I've been pleasantly surprised at how much I still like the ones I've tried so far.

Even the tea that wasn't in ideal storage still tastes good to me and I enjoy it, so I'll be using it either way, but I'm curious if this is just an example of how unsophisticated my taste is or if it's common to still find it palatable after years.

Oh, and, this applies to "traditional" greens, whites and black teas (I haven't ventured into pu-ehrs). All but one tasted really good to me. They all look and smell fine, too.

This is a subject I've been drifting into more lately, typically related to intentionally aged teas, but the subject of unintentionally aged teas overlaps. I just wrote a blog post review of a two year old black tea, but prior to that on much older teas, 21 year old and 30 year old oolongs:

I'm not really an expert, so nothing I say would be a last word, but my understanding is that tea essentially lasts forever, as long as relatively high humidity doesn't cause it to mold. It might improve, or it might be more typical for it to fade and lose flavor, with that range of different changes an interesting part. It's a good chance to just ramble on and on about different related factors, and there are many.

Related to tea type, of course pu'er is more or less intended to age, it ferments, most often seen as an improvement, but that depends on the tea, and storage factors, and preference. It's not unheard of for oolongs to intentionally be aged, overlapping with the practice just accidentally occurring. I wrote another review of a 40 year old Tie Kuan Yin that was just sort of set aside and lost. In general those oolongs seem to pick up an odd plummy taste, although that TKY was quite unusual, and the 30 year old tea was on the musty side.

Green teas are typically described as suffering from age--going through negative changes--most quickly, with black teas less likely to degrade quickly, but nothing is ever that simple. The vendor that let me sample that 40 year old tea had been drinking a Longjing (Chinese green tea) roughly that same age, at another time, so maybe there is precedence for some aging. White teas are the other main type most often described as being aged intentionally.

Then there are special cases. As an example, the darkest roasted Wuyi Yancha oolongs are said to improve with some aging, with the char effect wearing off over time (a year or two, or maybe improved more over a longer time-frame if roasted quite a bit).

To get back to the initial point, I wouldn't worry about drinking old tea unless there is some off characteristic or appearance that seemed like a warning sign. A white tea, a Silver Needle, that I lost track of for a year had darkened a bit in Bangkok weather storage conditions, and that didn't seem like a problematic change. Teas that experienced some degree of air contact, not stored sealed, would likely age differently, probably in general not well. But I also wouldn't be surprised if there were variations related to that I'm not aware of, other cases beyond pu'er for which limited air contact is not problematic. For example, I'm not really familiar with best-practices or related factors for storing other tea types pressed into cakes to enable aging.

john.b wrote:This is a subject I've been drifting into more lately, typically related to intentionally aged teas, but the subject of unintentionally aged teas overlaps. I just wrote a blog post review of a two year old black tea, but prior to that on much older teas, 21 year old and 30 year old oolongs:

I'm not an expert either, and after 7 years of drinking loose leaf tea I still consider myself very much a tea novice. That said, my impression, too, is that the green teas are generally the ones to suffer the most when left to age, particularly in less than perfect circumstances. Of the re-discovered greens I've tried so far, I'm pleasantly surprised that they're no worse for the wear.

It's interesting that some TGY teas are said to improve with age; mine certainly hasn't lost anything over the past 5 - 6 years and it might even taste better to me now. My oolongs are light and medium roast, which I've always considered to be fairly similar to green tea (in terms of processing), so this was a happy discovery.

All in all, I'm pretty happy to have stumbled onto a tea habit, and onto this forum in particular. Thanks for your input. I look forward to checking out your blog!

Related to that same subject and green tea, I had a version this morning that works as an example. A bit of an unusual case, a Chinese tour operator passed on a good bit of two versions of green tea from North Korea earlier this year (really!).

I initially thought one was supposed to be a black tea, since they looked the same, like Longjing, but the color differed, but now I think one was probably a sample of a year-older tea (so the review I wrote is probably not as clear as could be on that, even though I left it open). The teas are aging fast in Bangkok, due to heat and additional oxidation, but they're not really getting worse, just changing. They lose that bright freshness (which the darker version sort of never had), but pick up additional complexity, or just flavor shift that doesn't necessarily generalize.

I have also experienced some teas just flattening out. A local vendor mentioned that to maintain freshness, the original character, the best approach is to refrigerate the teas, of course very well sealed to prevent them from tasting like a refrigerator. Local Chinatown vendors will do this for Longjing, not so much for other tea types.

About sealing teas, it's sort of a given but standard practices used for food storage don't necessarily work well enough. "Baggies" are quite porous, relatively, in comparison to multi-layered bags designed to isolate air contact better. A twist-tie sealed bag is also not as effective as a well designed self-sealing closure.